The argument about not knowing what comes out of the pump - ghey. You buy a $15 tester and thats that. Tune it on class 3, where you are running essentially e70 and leave a little on the table and so long as you know whats coming out of that pump you have no issues..

Because if you tune it for e70 you reduce the timing and you almost back to what 93 octane offers but with less safety , now you thinking , keep going you will get there , you basicly saying to detune the e85 for safety like your running e70 , might as well use 93